Pest infestation of any object or body, such as in wood construction, or living plants, plant products or trees can be damaging to many areas of society. In the field of agriculture, pest infestation reduces the quality and quantity of harvestable crops. This causes an economic loss to the harvester, which in turn raises the price of these crops for the consumer. Furthermore, pests carry and spread diseases which are harmful to both the environment and to humans. Shipments of goods, particularly food products, are typically entirely discarded if even only one box is found to be carrying pests, which causes tremendous financial loss.
One example of a body in which pests particularly enjoy infesting is the tree. Trees play a vital role in many aspects of the subsistence of the world and its inhabitants, in such areas as ecology and agriculture, as well as in providing energy and raw material for such things as paper and lumber. One example of a tree species which is considered to be important to both natural landscape and for cultivation of its fruit is the Phoenix dactylifera L., or, the date palm.
Since antiquity, date palm distribution has been mainly concentrated throughout Mediterranean countries, Africa and part of Asia. In the past century, however, the date palm was introduced to North America, Australia and throughout Europe. Date production is currently a world agricultural industry, producing millions of metric tones of fruit a year, and marketed all over the world as a high-value confectionery and fruit crop. Moreover, the main ornamental tall palm planted in the gardens and the streets of many coastal cities are palm trees.
Despite its popularity amongst humans, diseases and pests plague the date palm tree. One such pest is the Rhynchophorus ferrugineus, or, the red palm weevil (RPW), also commonly known as the Indian palm weevil. The RPW was first observed in the Middle East region in the mid-1980's and have since been detected in trees in at least 19 countries around the world. As of the mid-1990's, approximately 5-6% of date palms in the Middle East were infested with the RPW, at an increasing annual rate of infestation (Food and Agriculture Organization of the United Nations, (FAO)). The cause of the high rate of spreading of the RPW is human intervention, by transporting infested young or adult date palm trees and offshoots from contaminated to uninfected areas. Currently, in all countries, it is illegal to transport a date palm tree in any form, even within the country itself. Moreover, in light of international laws, countries are required to report sightings of the RPW to the FAO.
Infestation is often not apparent until extensive damage has already been caused, and the tree is beyond recovery, resulting in the death of the tree. Infestation can be observed by wilted or yellow inner leaves and smelled by a characteristic rotting odor. Small round holes at the sites of removed offshoots and oozing out of a reddish brown fluid are also a clear indication of the presence of the RPW. Additionally, cocoon, weevil and pupal fibers are frequently found in the palm leaf base. The clearest sign of infestation is a tree that has fallen due to internal rotting.
Adult females lay several hundred eggs at the base of young leaves or in wounds to the leaves or trunk. Damage to date palms is caused mainly by the larvae, which hatch after 2-5 days. The hatched larvae burrow into the trunk and feed on the soft fibers and tissues of the stem. Just prior to pupating, they move towards the exterior of the tree, making tunnels and large cavities along the way. They can be found any place along the length of the tree. The larval period lasts from about 1-3 months when the larvae pupate inside fibrous cocoons and emerge as adults.
Generations of the RPW at all life stages can be present within a single palm tree. Typically, adult weevils present in a palm will not move to another one while they can still feed on it.
Measures that have been taken to prevent the spread of RPW have not been successful. The late detection of the presence of the RPW constitutes a serious problem in battling the pests. Despite various attempts, no safe techniques for early and consistent detection have been devised.
Nevertheless, there have been numerous measures devised for ridding trees of these pests. One common method of treatment comprises injecting chemical insecticides, including synthetic pesticides and botanicals, in either liquid or gas form, into the tree or individual insects. Anti-microbial products, which kill the micro-organisms that grow on the wood and in the stomach of the RPW may also be added. However, use of intensive chemical treatments (e.g. ConfidorR (Bayer)) has not been fully effective, and concerns have arisen over the environmental impact of the use of such chemicals. An alternative method is to cut down infested palms and destroy them before adults emerge from the tree. Prophylactic treatment of palms with insecticides is also an option, but the costs involved may be prohibitive. Mass trapping of RPW in buckets baited with cruentol and “pal esters” has high potential to reduce infestations.
One of the newest methods for monitoring and controlling RPW is bioacoustic methods, which measure sound emissions of the RPW at early stages of infestation. Sound emissions by the RPW can be detected and measured. Different sound emissions are classified into different groups for determining the lifecycle stage of the RPW, and the detection of the presence of the RPW is possible within only a few weeks of infestation of the tree.
Additionally, successful tests have been carried out in which dogs were used to locate infested trees. Insects feeding on plants produce a unique signature of chemical compounds, which can be smelled. Dogs are trained to recognize this smell and are sent to date palm plantations suspected of being infested with the RPW. (J. Nakash et al.; A Suggestion to Use Dogs for Detecting Red Palm Weevil (rhynchophorus ferrugineus) Infestation in Date Palms in Israel)
The infestation of the date palm tree by the RPW as described above is merely one example of an arthropod that causes destruction to an important tree species. Other arthropods that destroy the date palm tree include the Fruit Stalk Borer (Oryctes elegans) and the Stem Borer (Jebuses Hammerschidti). The Coconut Rhinoceros Beetle (Oryctes rhinoceros) is known to attack many species of palms including coconut, betel nut, sago palm and the dates. Many other significant species of trees throughout the world are vulnerable to infestation by various species of arthropods. One other example of an arthropod that damages trees is the moth (Zeuzera pyrina L.), which is known to cause serious damage to apple, pear and olive trees. The list of species of infested trees, as well as the list of species of infesting pests, is long, and methods of detection and treatment are generally chosen from at least one of those mentioned herein above, although other methods may be used as well.
U.S. Pat. No. 4,283,629 discloses a method and apparatus for detecting disease in a tree. U.S. Pat. No. 4,283,629 is particularly concerned with recognizing damage caused by red rot disease of a tree early in the infestation of a living tree. Red rot is caused by the fungus Fomes Annosus, which attacks mainly needle trees, such as spruce and pine, as well as the larch, Douglas fir and others. The fungus mainly grows in standing (live) trees, and moves upwardly from the bottom of the trunk. It causes a root rot, which, in the pine ultimately leads to the death of the tree, and in the spruce destroys the wood inside the trunk, but does not threaten its life. U.S. Pat. No. 4,283,629 utilizes computer tomography for measuring the coefficient of absorption of the trunk of the tree for gamma and/or neutron radiation. A change in the coefficient due to rot or other factors is detected. U.S. Pat. No. 4,283,629 does not attempt to identify the pest infesting the tree, but rather the cavities in the tree formed by the pest. A supporting frame surrounds and is preferably fastened to the trunk, a beam of radiation is passed through the tree at various positions from a radiation source to a detector and the coefficient of absorption at each position is converted into a computerized topographic display. U.S. Pat. No. 4,283,629 does not describe the means by which the apparatus is lifted and secured to the tree, although this does not appear to be a simple or standard procedure. Moreover, when desiring to use the apparatus of U.S. Pat. No. 4,283,629 on many trees, the dismounting and remounting procedure will take a lot of time, and will likely add to the costs involved.
It is an object of the present invention to provide a method and system for detecting the presence of pests in a body.
In one embodiment it is desirable to provide a method and system for the detection of the presence of pests in a body, which utilizes a portable (or, mobile) apparatus.
In one embodiment it is desirable to provide a method for the detection of pest infestation of a body, which utilizes an apparatus that is capable of being shifted along a predetermined length.
In one embodiment it is desirable to provide a method for the detection of the presence of pests in a body, which utilizes an apparatus that does not make physical contact with the tree during the detection process.
Additional advantages of the present invention will become apparent as the description proceeds.